Wellbore treatment system

ABSTRACT

A wellbore treatment system including a housing having a first port and a second port, a first sleeve positionable to cover and uncover the first port, a first supportable and unsupportable plug seat operably connected to the first sleeve, a second sleeve positionable to cover and uncover the second port and the first port, and a second supportable and unsupportable plug seat operably connected to the second sleeve. A method for treating a wellbore including deploying a plug to a first supportable and unsupportable plug seat operably connected to a first sleeve, actuating the first sleeve to open a first port in a housing, treating the wellbore through the first port, deploying a second plug to a second supportable and unsupportable plug seat operably connected to a second sleeve, and actuating the second sleeve to uncover a second port and cover the first port.

BACKGROUND

In the resource recovery industry, fracturing has become an oft employed operation to enhance target fluid recovery. In connection with a fracturing operation, it is necessary to open and close valves so that fracturing fluid may be forced to exit a tubing string to flow into the formation causing fractures. The valve may then need to be closed for various operations including fracturing another zone of the wellbore. There are various mechanical shifting operations for sliding sleeve valves and plug drop arrangements where the plug lands on a seat to shift a sleeve downhole but each of these has drawbacks that reduce efficiency. The industry is always receptive to improved systems that increase efficiency.

SUMMARY

A wellbore treatment system including a housing having a first port and a second port, a first sleeve positionable to cover and uncover the first port, a first supportable and unsupportable plug seat operably connected to the first sleeve, a second sleeve positionable to cover and uncover the second port and the first port, and a second supportable and unsupportable plug seat operably connected to the second sleeve.

A method for treating a wellbore including deploying a plug to a first supportable and unsupportable plug seat operably connected to a first sleeve, actuating the first sleeve to open a first port in a housing, treating the wellbore through the first port, deploying a second plug to a second supportable and unsupportable plug seat operably connected to a second sleeve, and actuating the second sleeve to uncover a second port and cover the first port.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 is a schematic view of a Wellbore Treatment System as disclosed herein;

FIG. 2 is the same view in second position;

FIG. 3 is the same view in third position; and

FIG. 4 is the same view in forth position.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring to FIG. 1 a wellbore treatment system 10 is illustrated schematically in quarter section. The system 10 includes a housing 12 having a first port 14 and a second port 16. The first port is intended to allow treatment fluid to reach the formation 18 when the port 14 is open. This treatment fluid may be a fracturing fluid, an acid, or any other type of fluid being applied to the formation 18. Port 16 is intended to perform as a production port subsequent to closure of the treatment port 14 to allow formation fluids to enter the housing 12. Both ports 14 and 16 are initially closed for run in and remain so until they are called upon for use by sleeves 20 and 22 that cover the ports 14 and 16, respectively.

The sleeves 20 and 22 are operatively connected to a first supportable and unsupportable plug seat 24 and a second supportable and unsupportable plug seat 26, respectively. The connection between the respective sleeves and seats is by a first release member 28 and a second release member 30. The release members may be shear members or automatically retractable members or other release configurations common in the industry to selectively bind a first component to a second component and shed that binding at a selected time or upon a selected condition. It is also noted that the second sleeve 22 is also connected to the housing with a housing release member 32 that may be an extension of the second release member 30 and provide a distinct release plane as is seen in the figures or otherwise allow release at the selected time. Alternatively, the housing release member may be wholly separate therefrom.

Seats 24 and 26 are configured to catch a plug 34 or 38 of the appropriate size (see example in FIG. 1 first seat). Axiomatically, the first seat will employ a plug with smaller dimensions than the second seat so that the first plug will pass through the second seat on its way to the first seat without significant interference. The seats 24 and 26 also are deformable at least in the region where the seat is configured to catch a plug. This allows under certain circumstances for the seats to be deformed thereby allowing a plug otherwise seated therein to pass through the seat. Resulting, after the treatment with the system 10, plugs will pass through the system 10 and fall to a gravitationally dictated spot in the well that is generally “out of the way” leaving the system 10 patent for production or further well operations.

Further edification will come through a discussion of operation of the system 10. The system 10 is to be installed in a wellbore as a part of a tubing string 36. When it is time to treat the formation 18, a first plug 34 is dropped into the wellbore. The plug 34 passes through seat 26 due to dimensions and then is caught by seat 24. Once caught, the operator applies pressure to the wellbore causing the seat 24 and the attached sleeve 20 to move to the right in FIG. 1 to the position shown in FIG. 2, thereby opening the first port 14. In the position shown in FIG. 2, the system 10 is ready for a treatment of the formation 18 through port 14. Subsequent to the treatment, a second plug 38 is dropped to land in seat 26. Pressure is applied to the plug 38 in seat 26 to release the housing release member 32, allowing the sleeve and seat 26 to move toward the seat 24, thereby uncovering port 16. Movement of seat 26 and sleeve 22 continues until a nose 40 of sleeve 22 comes in contact with sleeve 20 or with a component 42 of first release member 28 and pushes that component away from the release member 28. The action of pushing the component 42 away from member 28 releases the illustrated member 28, which is spring loaded so that it will disengage from the seat 24. Other release members could, of course, be substituted. Upon nose 40 making contact with sleeve 20, the second release member 30 will release, thereby allowing the second seat 26 to continue moving toward seat 24. Ultimately, seat 26 will crash into seat 24 encouraging the full release of first release member 28 and cause seat 24 to move in the downhole direction. Also during the motions of the two seats 24 and 26, it will be appreciated in FIG. 4 that a portion 44 and 46 of each of seats 24 and 26 are illustrated to be radially outwardly deflected into areas 48 and 50 of sleeves 20 and 22 respectively where support for the seat 24 and 26 is lacking. Accordingly, the portions 44 and 46 will naturally deform radially outwardly under the influence of the fluid pressure acting on the plugs 34 and 38, whereafter the plugs 34 and 38 will fall to an “out of the way” position. It is to be understood that the sequence of events described can occur quite rapidly such that one or more of the events might appear to occur simultaneously.

Set forth below are some embodiments of the foregoing disclosure:

Embodiment 1

A wellbore treatment system including a housing having a first port and a second port, a first sleeve positionable to cover and uncover the first port, a first supportable and unsupportable plug seat operably connected to the first sleeve, a second sleeve positionable to cover and uncover the second port and the first port, and a second supportable and unsupportable plug seat operably connected to the second sleeve.

Embodiment 2

The system as in any prior embodiment wherein the first sleeve and first seat are operably connected by a first release member.

Embodiment 3

The system as in any prior embodiment wherein the second sleeve and second seat are operably connected by a second release member.

Embodiment 4

The system as in any prior embodiment wherein the second sleeve is operably connected to the housing by a housing release member.

Embodiment 5

The system as in any prior embodiment wherein the second release member and the housing release member are one piece.

Embodiment 6

The system as in any prior embodiment wherein at least one of the first and second seat is radially outwardly deformable when unsupported.

Embodiment 7

The system as in any prior embodiment wherein the at least one of the first and second seat is elastic.

Embodiment 8

The system as in any prior embodiment wherein the at least one of the first and second seat is segmented.

Embodiment 9

The system as in any prior embodiment wherein segmented comprises collet fingers.

Embodiment 10

The system as in any prior embodiment wherein the first sleeve includes a recess where support for the first seat is lacking.

Embodiment 11

The system as in any prior embodiment wherein the second sleeve includes a recess where support for the second seat is lacking.

Embodiment 12

The system as in any prior embodiment wherein the second sleeve includes a nose configured to cover the first port.

Embodiment 13

The system as in any prior embodiment wherein the nose is configured to interact with the first release member.

Embodiment 14

A method for treating a wellbore including deploying a plug to a first supportable and unsupportable plug seat operably connected to a first sleeve, actuating the first sleeve to open a first port in a housing, treating the wellbore through the first port, deploying a second plug to a second supportable and unsupportable plug seat operably connected to a second sleeve, and actuating the second sleeve to uncover a second port and cover the first port.

Embodiment 15

The method as in any prior embodiment wherein the actuating the second sleeve includes releasing a housing release member.

Embodiment 16

The method as in any prior embodiment wherein the actuating the first sleeve includes pressuring on the first plug.

Embodiment 17

The method as in any prior embodiment wherein the actuating the second sleeve includes pressuring on the second plug.

Embodiment 18

The method as in any prior embodiment further including releasing a first release member operably connecting the first seat to the first sleeve, releasing a second release member operably connecting the second seat to the second sleeve, moving the first and second seats to positions adjacent the first and second sleeves respectively that lack support for the first and second seats, deforming the first and second seats, and releasing the first and second plugs.

Embodiment 19

The method as in any prior embodiment wherein the first and second sleeves include first and second recesses, respectively, and the moving of the first and second seats is to positions where the first and second seats are deformable into the first and second recesses, respectively.

Embodiment 20

The method as in any prior embodiment wherein the actuating the second sleeve to uncover a second port and cover the first port further includes releasing the first release member with the second sleeve.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should further be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity).

The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and/or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.

While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. 

What is claimed is:
 1. A wellbore treatment system comprising: a housing having a first port and a second port; a first sleeve positionable to cover and uncover the first port; a first supportable and unsupportable plug seat operably connected to the first sleeve; a second sleeve positionable to cover and uncover the second port and the first port; and a second supportable and unsupportable plug seat operably connected to the second sleeve.
 2. The system as claimed in claim 1 wherein the first sleeve and first seat are operably connected by a first release member.
 3. The system as claimed in claim 1 wherein the second sleeve and second seat are operably connected by a second release member.
 4. The system as claimed in claim 3 wherein the second sleeve is operably connected to the housing by a housing release member.
 5. The system as claimed in claim 4 wherein the second release member and the housing release member are one piece.
 6. The system as claimed in claim 1 wherein at least one of the first and second seat is radially outwardly deformable when unsupported.
 7. The system as claimed in claim 6 wherein the at least one of the first and second seat is elastic.
 8. The system as claimed in claim 6 wherein the at least one of the first and second seat is segmented.
 9. The system as claimed in claim 8 wherein segmented comprises collet fingers.
 10. The system as claimed in claim 1 wherein the first sleeve includes a recess where support for the first seat is lacking.
 11. The system as claimed in claim 1 wherein the second sleeve includes a recess where support for the second seat is lacking.
 12. The system as claimed in claim 1 wherein the second sleeve includes a nose configured to cover the first port.
 13. The system as claimed in claim 12 wherein the nose is configured to interact with the first release member.
 14. A method for treating a wellbore comprising: deploying a plug to a first supportable and unsupportable plug seat operably connected to a first sleeve; actuating the first sleeve to open a first port in a housing; treating the wellbore through the first port; deploying a second plug to a second supportable and unsupportable plug seat operably connected to a second sleeve; and actuating the second sleeve to uncover a second port and cover the first port.
 15. The method as claimed in claim 14 wherein the actuating the second sleeve includes releasing a housing release member.
 16. The method as claimed in claim 14 wherein the actuating the first sleeve includes pressuring on the first plug.
 17. The method as claimed in claim 14 wherein the actuating the second sleeve includes pressuring on the second plug.
 18. The method as claimed in claim 14 further comprising: releasing a first release member operably connecting the first seat to the first sleeve; releasing a second release member operably connecting the second seat to the second sleeve; moving the first and second seats to positions adjacent the first and second sleeves respectively that lack support for the first and second seats; deforming the first and second seats; and releasing the first and second plugs.
 19. The method as claimed in claim 18 wherein the first and second sleeves include first and second recesses, respectively, and the moving of the first and second seats is to positions where the first and second seats are deformable into the first and second recesses, respectively.
 20. The method as claimed in claim 14 wherein the actuating the second sleeve to uncover a second port and cover the first port further includes releasing the first release member with the second sleeve. 